In the mid-1990s, President Bill Clinton made a bold legal claim: He couldn’t be subjected to civil lawsuits for his actions as a private citizen until after his presidency ended. As you can imagine, that assertion raised eyebrows across the legal community. Among its critics was George Conway, a prominent New York City lawyer, who wrote in a 1994 Los Angeles Times op-ed that the claim “smacks of the privilege of a sovereign or an autocrat—not a president of a democratic republic.”

Clinton was then in the middle of a heated legal battle with Paula Jones, a former Arkansas state employee who alleged Clinton sexually harassed her in a hotel room while he was governor. The case eventually led to Clinton’s impeachment after he lied under oath about an affair with White House intern Monica Lewinsky during depositions in the Jones case. That scandal was still a few years away when Conway wrote his op-ed; his focus instead was on the troubling implications of Clinton’s presidential immunity claim.

“In the end, Clinton's immunity argument is unacceptable because it would place presidents above the law,” Conway wrote. “It would enable a president to take out a mortgage on a summer home, refuse to make payments and yet be immune from foreclosure for four or eight years. A president who owned a recreational speedboat could run someone over and postpone a suit by the victim's family, who would be left without redress for many years.”

The Supreme Court eventually vindicated that stance with a unanimous ruling against the president in 1997. “[Clinton’s] principal submission—that ‘in all but the most exceptional cases,’ the Constitution affords the president temporary immunity from civil damages litigation arising out of events that occurred before he took office—cannot be sustained on the basis of precedent,” Justice John Paul Stevens wrote for the Court.

Now, more than two decades later, Conway is slated to become the next head of the Justice Department’s Civil Division. And the man who picked him will be taking the opposite stance on presidential immunity in court.

In a defamation lawsuit currently underway in New York, President Trump’s private lawyers asked the judge Monday to set a special briefing schedule to address an unusual question: whether the court has the authority to “assert jurisdiction over the President and adjudicate this case during his time in office.”

In other words, Trump asked the court to consider whether he can be sued in his private, unofficial capacity during his presidency. “Declining to consider would undermine not only judicial economy, but the very immunity he asserts and which the United States Constitution affords him by compelling him to litigate this action on the merits before that immunity is resolved,” his attorneys said in the filing. Trump’s lawyers did not provide an extensive argument for the immunity’s existence, which would instead be made if the court grants the special briefing. Instead they asserted the immunity was based on the Supremacy Clause, which declares the Constitution to be the supreme law of the land.

But whether that immunity even exists is an open question: The Supreme Court only ruled in 1997 that the president could be sued for his private acts in federal courts, leaving open the question whether he could face lawsuits for those acts in state courts. (Presidents enjoy a separate immunity from civil lawsuits for their official acts in both state and federal courts.) That makes Trump’s claim an increasingly rare event in the American legal system: a wholly novel question of constitutional law.

Trump’s lawyers made the assertion in response to a lawsuit brought by Summer Zervos, a contestant on NBC’s The Apprentice when Trump hosted it. The case’s origins date to the closing weeks of the 2016 presidential campaign when the Washington Post published a 2005 Access Hollywood tape in which Trump bragged about committing sexual assault to host Billy Bush. Multiple women then came forward to accuse him of misconduct over the past three decades. Among them was Zervos, who alleged Trump had kissed and groped her during a meeting at a Beverly Hills hotel in 2007.

Trump has repeatedly denied any wrongdoing in this case and others. And in his usual fashion, he also denounced many of the women who accused him of misconduct and accused them of lying to harm his presidential campaign. “Every woman lied when they came forward to hurt my campaign, total fabrication,” he said, according to Zervos’s complaint. “The events never happened.” Those denunications prompted Zervos to sue him for defamation, seeking an apology and about $2,500 in damages.

But if Trump has his way, the merits of her lawsuit won’t be heard for at least four years. Even the most basic preliminary proceedings should be halted, his lawyers argued, advancing an expansive conception of presidential immunity. “Requiring President Trump to litigate the merits on a motion to dismiss the complaint, in addition to moving to dismiss on grounds of presidential immunity, would negate the very interests that that immunity is designed to protect,” the filing said.

Clinton v. Jones, which Trump’s lawyers cited multiple times in their filing, presented a novel constitutional question for the justices two decades ago. To keep its ruling narrow, the Court said it would decline to address two issues. One was whether courts could compel the president to appear at any time or place—a potentially onerous requirement for the nation’s chief executive. The other unresolved question was whether presidential immunity from civil lawsuits existed in state courts. Jones’s lawsuit was filed in federal court, raising separation-of-powers questions for the Supreme Court to resolve. A lawsuit in a state court, the justices noted, would revolve around federalism concerns instead. Monday’s filing by Trump aims to resolve that open question.

On a historical level, presidents were almost never sued in their private capacity before Clinton. Only Theodore Roosevelt, Harry Truman, and John F. Kennedy had faced civil lawsuits for their pre-office conduct while president at that point, according to the Court. And those cases were also relatively trivial in nature: The lawsuits against Roosevelt and Truman were eventually dismissed, while the case against Kennedy, which sprung from a car accident in which he was involved, was settled out of court.

Trump’s private legal affairs are far more complex, to say the least. The president was notoriously litigious during his decades as a real-estate businessman: An extensive USA Today investigation during the 2016 presidential campaign estimated Trump had been involved in more than 3,500 lawsuits, both as a plaintiff and as a defendant, in his business career. In October, the newspaper found at least 75 pending cases involving Trump ahead of Election Day. It’s not immediately clear how many of those lawsuits are still ongoing today; he settled at least one high-profile case—with former customers of the now-defunct Trump University—before his inauguration.

If the courts adopt a presidential immunity rule for state-level civil lawsuits, the impact could be devastating for those suing Trump. Prolonged litigation can be costly in almost every sense—in time, energy, and most of all, money. Suspending those proceedings for at least four years would be a significant boon for someone with Trump’s resources, who’s in a better position to outlast less-wealthy plaintiffs. And if he’s re-elected in 2020, currently active cases would go unresolved for almost a decade.

There are good reasons for the courts to grant presidents some procedural leeway when facing civil litigation, for both the White House’s benefit and for the country. But when it comes to a claim of immunity—even a temporary one—Trump’s choice to become the federal government’s top civil litigator summarized it best.

“In a case involving his private conduct, a president should be treated like any private citizen,” Conway wrote. “The rule of law requires no more—and no less.”